Demagnifying high-resolution imaging based on a new system for nanolithography

Abstract

A novel subdiffraction-limited photolithography design with demagnification and high contrast features has been presented in this paper. Alternating phase shift mask (Alt-PSM) is not only used for shifting phase between adjacent aperture pairs through the phase shifter, but also it enhances the transmission by the interference of diffracted evanescent waves from subwavelength apertures at the surface. Research results show that the combination of Alt-PSM and planar hyperlens can realize subwavelength plane-to-plane imaging beyond the diffraction limit. Furthermore, with a well-proportioned reduction factor of 2, the resolution down to 60 nm can be easily attained from an Alt-PSM with 255 nm period at a working wavelength of 365 nm. Actually finer resolution can be obtained if we properly optimize the parameters of the mask and the planar hyperlens.